Research

RTD Nanopillars

[research]

InAs/InP NP with double barrier heterostructures are grown by metal-organic chemical vapor deposition (MOCVD) via selective-area epitaxy. By reducing the sandwiched InAs thickness to small dimensions (~ 15 nm), quantized structures can be formed. Having thin InP barriers can also allow tunneling through these barriers, hence forming resonant tunneling diodes (RTDs) in these NPs. From the single-NP devices, we can measure negative differential resistance in both positive and negative bias regions at 77K with a peak-to-valley ratio of 1.7. RTDs have been shown to have inherently high oscillation frequency (~THz) from resonant tunneling mechanism. With our NP approach, these RTDs can also be grown on Si substrate, making such device structure a potential candidate for high-speed oscillator integrated on Si.